Fiber-optic Lorentz force magnetometer based on a gold-graphene composite membrane

Abstract

Because of its outstanding mechanical and electronic properties and unique transfer flexibility, graphene is ideal for miniature all-in-fiber nanoelectromechanical systems (NEMS) in ultrasensitive sensing applications; however, its application in magnetic detection is limited because of the lack of magnetic-optic response. Here, we demonstrate a high spatial resolution fiber-optic magnetic field sensor based on Lorentz force in a pseudo–magnetic-response quasi-static graphene NEMS. The ultra-compact design of this all-fiber-based sensor is achieved by integrating a hybrid gold-graphene membrane and two gold electrodes onto the hollow endface of a single-mode fiber. An electrical current flowing through the suspended membrane in a perpendicular magnetic field can generate Lorentz force to cause a nanoscale deformation of the membrane. The sensor has a much higher spatial resolution, which is nanometer-scale longitudinally, compared with conventional optical fiber magnetic sensors.